(a) Field of the Invention
This invention relates to 1,2-dihydro-6-substituted-2-oxo-5-(pyridinyl)nicotinonitrile derivatives, their use as a cardiotonic agents, and their preparation.
(b) Description of the Prior Art
Belgian Pat. No. 886,336, granted May 25, 1980, shows, inter alia, 1,2-dihydro-6-methyl-2-oxo-5-(pyridinyl)nicotinonitriles as cardiotonic agents. These compounds also are disclosed and claimed in copending Lesher and Philion U.S. patent application Ser. No. 198,461, filed Oct. 20, 1980 and now U.S. Pat. No. 4,313,951 issued Feb. 2, 1982, a continuation-in-part of application Serial No. 97,504, filed Nov. 26, 1979 and now abandoned.
Lesher, Opalka and Page U.S. Pat. No. 4,276,293, issued June 30, 1981, discloses inter alia as intermediates 1,2-dihydro-6-methyl-2-oxo-5-(pyridinyl)nicotinonitriles.